More specifically, the invention relates to a method for notifying, to a telephone terminal, placed behind an access gateway to a telecommunication network such as a voice-over-IP network (IP standing for Internet Protocol), the fact that a communication is in progress on another telephone terminal connected to this gateway.
With the growing development of voice-over-IP services, such gateways, also called domestic gateways, are now known, behind which it is possible to connect a plurality of terminals to distinct ports, in order to benefit from various services, such as Internet access, television over IP, voice over IP, etc.
In the context of the invention, only telephone terminals connected to such a gateway are considered. For the purposes of clarity and concision, the terminals mentioned hereinafter in this application are therefore, unless otherwise specified, telephone terminals.
The telephone terminals connected behind such a domestic gateway are generally associated with a same public telephone identifier or number on the voice-over-IP network (for example, an SIP address) to which the gateway is connected. In such a case, the gateway is called single-line. Otherwise, if the domestic gateway is associated with a number of public identifiers, the gateway is called multiple-line.
Now, most of the domestic gateways are single-line, and generally operate in single-communication mode: a single simultaneous telephone communication between an external terminal and one of the terminals connected to the gateway can be set up. When such a communication is in progress, it is therefore not possible to initiate a telephone call from another terminal connected to the gateway, not involved in this communication. As it happens, there is no visual indication enabling the user of this other terminal to know that the line is busy, only the busy tone played to the user on lifting the handset providing this information.
Furthermore, the same problem arises for the domestic gateways that operate in multi-communication mode, that is to say, which enable a number of telephone communications to be set up simultaneously, when the number of telephone terminals connected to such a gateway exceeds the number of communications that can be managed simultaneously by this gateway.